Grassland: Selecting indicators of success for grassland enhancement (TIN050)

Cover of wildflowers in the sward


Indicator 11 refers to the cover of non-grasses in the sward including rushes and sedges, but excluding invasive weeds such as thistles, docks, common ragwort, common nettle, dandelions and white clover (these should be covered in the agreement prescriptions). On damper sites creeping buttercup can be abundant on species-poor sites and may be also excluded from this indicator.

Cover of non-grasses, with the above caveats, is a good indicator of grassland quality in many instances. The upper limit is usually set at 90%, recognising that grasses are integral to these habitats. The range allows for annual fluctuations and seasonal variation in response to weather. Flexibility of management in relation to weather is particularly important in year 1, for example in wet seasons extensive grass growth may require extra management and/or may mean that the indicator is not met.

The percentage of broadleaved species in flower is optional indicator and can be used to discourage overgrazing. It may be particularly useful when no stocking rates are prescribed. The indicator should ensure that grazing levels in spring and early summer are low enough to allow desirable species to flower and set seed. This is less appropriate for hay meadows, which are not grazed during the main flowering period.

This indicator allows an agreement holder to take ownership of assessing progress even if they can't identify the different species. However, they should be aware that early high proportions of broadleaved species may be followed by a low while the more difficult species become established.

Agreement year

The year set might vary according to the treatment of the site. Assuming some significant intervention (e.g. spreading species-rich green hay) a step increase would be expected in the year after such treatment. On some sites restoration grazing might be heavy early in the agreement in order to reduce the dominance of species such as tor-grass. While in this restoration phase a lower percentage of broadleaved species in flower will be acceptable.

Timing

The default figure of 40% of broad-leaved species in flower might be varied in particular circumstances. The specified months will also vary according to the particular site and its management objectives. May-June is a period when many species will be flowering on most southern lowland sites. For certain Lowland Acid Grassland sites, with spring-flowering annuals, this period could be set as April-May or earlier. Where the sward has a high proportion of relatively late flowering plants, such as common knapweed, devil's-bit scabious and common fleabane, the period may extend to include August.

This indicator can be used to monitor the effectiveness of management for other species. For example, the small blue butterfly needs a good proportion of kidney vetch flowers left uneaten because this is where the larvae live.

Frequency/Density/% Cover

The following are suggested as default values:

They should be assessed during the spring and summer.

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